The invention relates to a diagnostic radiology installation comprising a patient support, a radiation measuring arrangement comprised of a radiation source which generates a fan-shaped radiation beam penetrating the radiography subject and disposed transversely to the patient support, and a radiation receiver which is formed of an array of detectors, means for generating relative movement between the patient support and the radiation measuring arrangement, and a measurand processing circuit for producing an image of the body region scanned during the relative movement.
Diagnostic radiology installations of this type are known in which the measuring arrangement is mounted for rotation about an axis extending parallel to the longitudinal axis of the patient support such that a transverse layer of the patient can be scanned from different projections. Accordingly, the measurand processing circuit then determines an image of the scanned transverse layer. Diagnostic radiology installations of this type are designated as computer tomographs. A computer tomograph of this type is described, for example, in the German OS 27 41 732.
In the case of this known computer tomograph, two radiation receivers, comprised of one detector array, respectively, are provided parallel to one another and adjacent one another, one of which being respectively utilized for the purpose of image-formation. The radiation receivers have different lengths. Given the same number of detectors, a different image resolution thus results in each instance, since the scanned region is smaller in the one case than in the other case. The utilization of two radiation receivers allows the taking into account of the desired image resolution; however, it signifies a considerable outlay.
A diagnostic radiology installation of the type initially cited is also known in which a relative movement between the patient support and the radiation measuring arrangement takes place in a longitudinal direction of the support (German OS 26 13 809). Through this diagnostic radiology installation it is possible to prepare a synoptic radiograph of the body region of the patient scanned during displacement in the longitudinal direction of the support. During this displacement, the measuring arrangement is locked against rotation. In this instance, also, there is the desire to be able to vary the image resolution; i.e., to be able to vary the effective number of detectors per unit of length of a straight line running perpendicularly to the central ray of the radiation beam in the plane of the fan.